如何使用reqwest发布文件?
reqwest v0.9.18的文档显示了以下发布文件的示例:
let file = fs::File::open("from_a_file.txt")?;
let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
.body(file)
.send()?;
reqwest v0.11的最新文档不再包含此示例,并且在调用时尝试构建它失败并出现以下错误body():
the trait `From<std::fs::File>` is not implemented for `Body`
发送文件的更新方法是什么?
回答
您链接到的特定示例是在使用 async的reqwest板条箱之前。如果你想使用那个确切的例子,那么reqwest::Client你需要使用reqwest::blocking::Client. 这也需要启用该blocking功能。
需要明确的是,实际上你可以仍然发现,例如,它只是坐落在文档的reqwest::blocking::RequestBuilder的body()方法来代替。
// reqwest = { version = "0.11", features = ["blocking"] }
use reqwest::blocking::Client;
use std::fs::File;
fn main() -> Result<(), Box<dyn std::error::Error>> {
let file = File::open("from_a_file.txt")?;
let client = Client::new();
let res = client.post("http://httpbin.org/post")
.body(file)
.send()?;
Ok(())
}
还要检查reqwest'sForm和RequestBuilder'smultipart()方法,因为例如有一个file()方法。
如果您确实想使用异步,那么您可以使用FramedReadfrom tokio-utilcrate。随着TryStreamExt特性,来自futures板条箱。
只要确保启用stream的功能reqwest,以及codec为特征tokio-util。
// futures = "0.3"
use futures::stream::TryStreamExt;
// reqwest = { version = "0.11", features = ["stream"] }
use reqwest::{Body, Client};
// tokio = { version = "1.0", features = ["full"] }
use tokio::fs::File;
// tokio-util = { version = "0.6", features = ["codec"] }
use tokio_util::codec::{BytesCodec, FramedRead};
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let file = File::open("from_a_file.txt").await?;
let client = reqwest::Client::new();
let res = client
.post("http://httpbin.org/post")
.body(file_to_body(file))
.send()
.await?;
Ok(())
}
fn file_to_body(file: File) -> Body {
let stream = FramedRead::new(file, BytesCodec::new());
let body = Body::wrap_stream(stream);
body
}